Method and system for adsorbing, purifying, enriching and recycling nitrogen oxides in flue gas

Abstract

The invention belongs to the technical field of gas recycling in flue gas, and particularly relates to a method and system for adsorbing, purifying, enriching and recycling nitrogen oxides in flue gas. The method comprises the steps that firstly, the flue gas is desulfurated, cooled, dehydrated and re-cooled on the premise of ensuring that the flue gas does not form acid or dew in the transportation process, and the content of NOX components is not reduced; then sulfur-free and anhydrous flue gas at normal temperature is introduced into an adsorber to adsorb the NOX for desorption; after adsorption is saturated, an adsorbent is desorbed and regenerated in a heating and negative pressure mode to obtain mixed desorbed gas with high concentrations of NO2 and NO; finally, a rectification method is adopted for liquefying, separating and concentrating the desorbed gas to obtain high-purity NO2 liquid-state and NO gas-state products. The method overcomes the defects of existing methods for lossless enriching and recycling of NOX in the flue gas, and the NO and NO2 products with very high added values are formed while the NOX in the flue gas is efficiently desorbed; meanwhile, the waste heat resource is sufficiently utilized, and compared with the prior art, the method and system have more obvious economic benefits.

Description

technical field [0001] The invention belongs to the technical field of gas recovery from flue gas, and in particular relates to a method and system for adsorption, purification, enrichment and recovery of flue gas nitrogen oxides. Background technique [0002] Industrial flue gas contains a large amount of SO 2 and NO X and other pollutants, the concentration is usually 200-1500mg / Nm 3 , often use wet or semi-dry desulfurization, SCR catalytic denitrification and other technologies to digest and remove them or convert them into other wastes. In fact, high-purity NO 2 And NO has important application value in metallurgy, chemical industry, medicine and many other fields, and these components in flue gas should be their important sources. Separation, enrichment and resource utilization of flue gas pollutants has become an important pollution control trend of the green economy, but to effectively realize this technical route, there are still two bottlenecks: (1) NO in flue ...

AI Technical Summary

Problems solved by technology

There is no high-purity NO with higher added value extracted by rectification 2 , NO technical means, the main reason is that the NO X The adsorption capacity is low, it is difficult to regenerate to obtain a higher concentration and does not contain SO 2 NO with water X enriched gas

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